July 2017

Feature Articles

Gear Inspection at Light SpeedRevolutionary new inspection technologies are helping gear manufacturers develop and produce more complex, higher quality gears in a fraction of the time it used to take.

Ask Not What Your Heat Treater Can Do for You...When sending gears to be heat treated, manufacturers can end up unwittingly making mistakes that slow down turnaround
time. We talked to some heat treaters to get their best advice on how you can help them help you.

You Cannot Rely on Labor Efficiency ReportingIn manufacturing, we all know that
tracking statistics on your operation is
essential for understanding how you're
doing, as well as identifying areas for
improvement. But what does the efficiency
metric actually tell you?

Technical Articles

Contact Fatigue Characterization of Through-Hardened Steel for Low-Speed Applications like HoistingIn several applications like hoisting equipment and cranes, open gears are used to transmit power at rather low speeds (tangential velocity < 1m/s) with lubrication by grease. In consequence those applications have particularities in terms of lubricating conditions and friction involved, pairing of material between pinion and gear wheel, lubricant supply, loading cycles and behavior of materials with significant contact pressure due to lower number of cycles.

MicroPulse and MicroShift for Ground Bevel GearsetsGrinding of bevel and hypoid gears creates on the surface a roughness structure with lines that are parallel to the root. Imperfections of those lines often repeat on preceding teeth, leading to a magnification of the amplitudes above the tooth mesh frequency and their higher harmonics. This phenomenon is known in grinding and has led in many cylindrical gear applications to an additional finishing operation (honing). Until now, in bevel and hypoid gear grinding, a short time lapping of pinion and gear after the grinding operation, is the only possibility to change the surface structure from the strongly root line oriented roughness lines to a diffuse structure.

Surface Characteristics of Hobbed GearsGear hobbing is one of the most productive manufacturing processes for cylindrical gears. The quality of the gears is a result of the tool quality, the precision of the workpiece, tool clamping and kinematics of the machine. The dry gear hobbing process allows machining of gears with a quality according to the DIN standard up to IT 5. To evaluate which gear quality is possible to machine with a given clamping and hob, it is useful to simulate the process in advance.

Departments

Backlash in Bevel and Hypoid Gears (Ask the Expert)What is the relationship between angular backlash or mean normal backlash change and the axial movement of the ring gear in bevel and hypoid gears?

Calendar (Events)Upcoming conferences, trade shows and events from the July 2017 issue of Gear Technology.

Industry News (Industry News)AGMA adds two new committees, Star Cutter Celebrates 90 years, plus other news from around the industry.

Much Ado About Nothing (Addendum)For over 50 years, the Do Nothing Machine has entertained the public eye with its complex machinery, a mountain of over 700
gears put together for the express purpose of doing nothing.